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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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4e6a0535dd
On qemu, the backtrace would show up _after_ the "end of backtrace testing" message. This patch changes it to use completions instead, which will guarantee that no such race exists. Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
92 lines
2.1 KiB
C
92 lines
2.1 KiB
C
/*
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* Simple stack backtrace regression test module
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*
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* (C) Copyright 2008 Intel Corporation
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* Author: Arjan van de Ven <arjan@linux.intel.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; version 2
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* of the License.
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*/
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#include <linux/completion.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/stacktrace.h>
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static void backtrace_test_normal(void)
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{
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printk("Testing a backtrace from process context.\n");
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printk("The following trace is a kernel self test and not a bug!\n");
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dump_stack();
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}
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static DECLARE_COMPLETION(backtrace_work);
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static void backtrace_test_irq_callback(unsigned long data)
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{
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dump_stack();
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complete(&backtrace_work);
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}
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static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0);
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static void backtrace_test_irq(void)
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{
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printk("Testing a backtrace from irq context.\n");
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printk("The following trace is a kernel self test and not a bug!\n");
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init_completion(&backtrace_work);
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tasklet_schedule(&backtrace_tasklet);
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wait_for_completion(&backtrace_work);
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}
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#ifdef CONFIG_STACKTRACE
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static void backtrace_test_saved(void)
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{
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struct stack_trace trace;
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unsigned long entries[8];
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printk("Testing a saved backtrace.\n");
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printk("The following trace is a kernel self test and not a bug!\n");
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trace.nr_entries = 0;
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trace.max_entries = ARRAY_SIZE(entries);
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trace.entries = entries;
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trace.skip = 0;
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save_stack_trace(&trace);
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print_stack_trace(&trace, 0);
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}
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#else
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static void backtrace_test_saved(void)
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{
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printk("Saved backtrace test skipped.\n");
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}
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#endif
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static int backtrace_regression_test(void)
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{
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printk("====[ backtrace testing ]===========\n");
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backtrace_test_normal();
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backtrace_test_irq();
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backtrace_test_saved();
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printk("====[ end of backtrace testing ]====\n");
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return 0;
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}
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static void exitf(void)
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{
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}
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module_init(backtrace_regression_test);
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module_exit(exitf);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
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